山东半岛蓝色经济区土壤重金属潜在生态风险研究

摘要

以山东半岛蓝色经济区土壤为对象,研究土壤中重金属污染的特征,采用Hakanson潜在生态危害指数法评价了土壤中重金属的潜在生态危害.结果显示,Hg是半岛蓝色经济区首要重金属污染物,而Cd、Cu、Pb污染较为普遍,土壤重金属元素污染程度依次为Hg>Cd>Cu>Pb>Zn>Cr>As,而重金属潜在生态风险大小则依次为Hg>Cd>As>Pb>Cu>Cr>Zn.总体看来,该区存在一定程度的重金属污染,其潜在生态风险为强和很强的土壤占13.75％,这种综合危害特征主要受Hg和Cd元素制约,分布在莱州—招远—烟台、牟平—乳山金矿集中区以及人口密集的城镇地带,且已对农作物安全产生影响.地质背景和人类活动(采金污染、城市人口密集生活)的共同作用,是造成局部环境中重金属潜在生态风险较高的主要原因.%In this research, soil samples were collected from Shandong Peninsula Blue Economic Zone to investigate heavy metal pollutions in this region and to evaluate the potential ecological risks of heavy metal pollutants based on Hakanson Potential Ecological Risk Indexes. According to the results, Hg was the primary heavy metal pollutant in Blue Economic Zone, followed by Cd, Cu, and Pb as prevalent pollutants. Heavy metals ranked in order of their pollution degrees are:Hg>Cd>Cu>Pb>Zn>Cr>As; the potential ecological risks of heavy metals follow the order of Hg>Cd>As>Pb>Cu>Cr>Zn. Heavy metal pollutions did exist in this region to a certain extent, and the percentage of potential ecological risk in "strong"and "severe" degree reached up to 13.75％. This composite risk characteristic was subject to the restriction of Hg and Cd mainly distributed in Laizhou-Zhaoyuan-Yantai, Muping-Rushan Goldmine, and other densely-populated regions, threatening the safety production of crops. The combined effects of geological background and human activities, e.g. gold mining and domestic pollutants, were the main causes of high potential ecological risks of heavy metals in local environment.